Mechanism of action
Pre-oxidation of arsenic(III) to arsenic(V)
By transforming to one form of arsenic, simplifies arsenic removal by other means
Precipitation and coagulation
Co-precipitation of water insoluble arsenates and inorganic oxides of other metals
Granular adsorptive media
Filtration, electrical repulsion and adsorption
Water passes through an ion exchange resin which removes arsenic by exchanging it for non-toxic ions.
Sorption and oxidation, e.g. through bacteria, fungi and hyacinths
The top of shallow aquifers, at less than 10 m, appear to be less contaminated than deeper water.
Tubewells sunk below the layer of sediment considered to contain arsenic
Contaminated water is forced through a membrane. The treated water passes through leaving the arsenic ions on the membrane
Similar principle to reverse osmosis, with a nm pore size